The invention pertains to a catheter which is provided with a tube which is carried in an inverted position within the catheter and everted from the catheter during use.
Reference may be had to U.S. Pat. No. 4,109,659 as the most significant prior art of which we are aware as to the subject invention. The subject catheter differs from the one shown in that patent in several important regards which adapt the present catheter to a number of uses for which this prior art evagination catheter is not suitable. The principal differences between our catheter and this prior art catheter are: our tube is non-elastomeric; it has an inner diameter equal to or greater than the diameter of the catheter body; and the distal tip of the tube is folded in a manner to close off the previously open distal end of the tube and to maintain this distal end in closed condition until the full length of the tube has been everted from the catheter body. In the final phase of the tube eversion process, the folded tip flips to an inside-out condition, thus conditioning the tube end to unfolding to present a through lumen to the overall tubular extrusion catheter.